Samsung Galaxy Watch Ultra2 and Apple Watch Ultra 3 Bring AI Assistants and Health Sensors to Premium Wearables

Samsung’s Galaxy Watch Ultra2 and Apple’s Watch Ultra 3, both launched in 2026, represent the top tier of their respective smartwatch lines. While the two devices compete on hardware, a key differentiator for AI-savvy users is the presence of Google Gemini on the Samsung watch versus Apple’s Siri on the Apple model. This comparison, originally published by Xataka IA, examines design, battery, sensors, and ecosystem lock-in.

AI assistants on the wrist

The Samsung Galaxy Watch Ultra2 runs Wear OS 7 with One UI 9 Watch and includes Google Gemini as a built-in assistant, allowing users to interact with the AI model directly from the watch. Apple’s Watch Ultra 3 uses watchOS with Siri. Neither company has disclosed the full extent of on-device AI processing, but both watches support voice commands, notification handling, and health queries. The practical impact for users lies in the quality of responses and integration with other services—Gemini leverages Google’s ecosystem, while Siri is tied to Apple’s. The watches also support third-party apps, but the AI assistant experience will vary depending on the smartphone ecosystem.

Health monitoring and sensors

Both watches are oriented toward athletes and health-conscious users. The Galaxy Watch Ultra2 includes Samsung’s BioActive sensor, which combines heart rate, ECG, and bioelectrical impedance analysis, alongside sleep apnea detection and stress monitoring. The Apple Watch Ultra 3 offers SpO2, optical heart rate, ECG, accelerometer, gyroscope, altimeter, dual-frequency GPS, and VO2 max. Both devices can detect falls and car crashes. The health data is processed locally and on-device, but the AI algorithms that interpret the data are proprietary to each manufacturer. Neither company has published independent validation of the accuracy of these algorithms, so users should treat the readings as guidance rather than medical diagnoses.

Key facts

Battery and performance

The Galaxy Watch Ultra2’s battery capacity has grown to 800 mAh, with Samsung claiming up to 60 hours of uninterrupted use thanks to the new Snapdragon Wear Elite processor. Apple’s Watch Ultra 3 remains at 42 hours of rated battery life. Both figures are theoretical and will vary with usage, especially with always-on display and GPS tracking. The Samsung watch also supports faster charging, though exact times were not provided in the source. For users who rely on continuous health monitoring or AI assistant queries, longer battery life means fewer interruptions.

Ecosystem and compatibility

The biggest practical constraint is the smartphone ecosystem. The Galaxy Watch Ultra2 works only with Android phones, and some features—such as sleep apnea detection—are reserved for Samsung Galaxy phones. The Apple Watch Ultra 3 works only with iPhones. This means the choice of AI assistant (Gemini vs Siri) is largely predetermined by the user’s phone. For power users who want to manage both a watch and an AI assistant, the ecosystem lock-in is a significant factor. The watches also have different app stores: Wear OS supports Google Play, while Apple Watch uses the App Store.

Source: Xataka IA – “Samsung Galaxy Watch Ultra2 vs Apple Watch Ultra 3: en qué se parecen (y en qué no) más allá de compartir apellido” – https://www.xataka.com/seleccion/samsung-galaxy-watch-ultra2-vs-apple-watch-ultra-3-que-se-parecen-que-no-alla-compartir-apellido